I'd have a good listen to the attenuator before laying cash down. The last one I used was the Weber, it changed the tone of every amp I used it on. Even when it was switched in with no attenuation it rolled bass off. I tried it with my eighteen watt Marshall and it sounded very two dimensional. Needless to say I've ruled attenuators out as an option.
Hopefully Dave Friedman's one will succeed where others have failed.
Mark